Objective To explore the possibility of use of IVF-20 medium in rat in vitro fertilization(IVF) experiments,and provide a practical reference for embryo conservation.Methods Using IVF-20 as capacitation and fertilization medium,four strains of rats,including SD,Wistar,GK and F344 were chosen for the IVF experiment.The resulting IVF embryos were cultured in vitro with mR1EMC medium.Besides,some of 2-cell embryos were transferred into the oviducts of recipients after induction of pseudopregnancy.Results The cleavage rates of SD,Wistar,GK and F344 rats were 83.2%,72.6%,87.8% and 71.6%,respectively.The blastocyst development rate in SD rat was 16.7%,lower but with no significant difference than that(24.5%) of embryos produced in vivo.Both recipients transferred with embryos from IVF established pregnancy,and delivered 10 pups(12.5%).Conclusion IVF-20 medium used in human in vitro fertilization is also suitable for in vitro capacitation and fertilization in rats,resulting in good cleavage rate,as well as blastocyst development rate,and the 2-cell embryos from IVF can fulfill the complete development after transplantation and give birth to normal pups.